// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/cast/common/rtp_time.h"

#include <limits>
#include <sstream>

namespace media {
namespace cast {

    namespace {

        // Returns the base::TimeDelta nearest to the time represented by a tick count
        // in the given timebase.
        base::TimeDelta TicksToTimeDelta(int64_t ticks, int timebase)
        {
            DCHECK_GT(timebase, 0);
            const double micros = static_cast<double>(ticks) / timebase * base::Time::kMicrosecondsPerSecond + 0.5 /* rounding */;
            DCHECK_LT(micros, static_cast<double>(std::numeric_limits<int64_t>::max()));
            return base::TimeDelta::FromMicroseconds(static_cast<int64_t>(micros));
        }

        // Returns the tick count in the given timebase nearest to the base::TimeDelta.
        int64_t TimeDeltaToTicks(base::TimeDelta delta, int timebase)
        {
            DCHECK_GT(timebase, 0);
            const double ticks = delta.InSecondsF() * timebase + 0.5 /* rounding */;
            DCHECK_LT(ticks, static_cast<double>(std::numeric_limits<int64_t>::max()));
            return static_cast<int64_t>(ticks);
        }

    } // namespace

    std::ostream& operator<<(std::ostream& out, const RtpTimeDelta rhs)
    {
        if (rhs.value_ >= 0)
            out << "RTP+";
        else
            out << "RTP";
        return out << rhs.value_;
    }

    std::ostream& operator<<(std::ostream& out, const RtpTimeTicks rhs)
    {
        return out << "RTP@" << rhs.value_;
    }

    base::TimeDelta RtpTimeDelta::ToTimeDelta(int rtp_timebase) const
    {
        return TicksToTimeDelta(value_, rtp_timebase);
    }

    // static
    RtpTimeDelta RtpTimeDelta::FromTimeDelta(base::TimeDelta delta,
        int rtp_timebase)
    {
        return RtpTimeDelta(TimeDeltaToTicks(delta, rtp_timebase));
    }

    // static
    RtpTimeDelta RtpTimeDelta::FromTicks(int64_t ticks)
    {
        return RtpTimeDelta(ticks);
    }

    base::TimeDelta RtpTimeTicks::ToTimeDelta(int rtp_timebase) const
    {
        return TicksToTimeDelta(value_, rtp_timebase);
    }

    // static
    RtpTimeTicks RtpTimeTicks::FromTimeDelta(base::TimeDelta delta,
        int rtp_timebase)
    {
        return RtpTimeTicks(TimeDeltaToTicks(delta, rtp_timebase));
    }

} // namespace cast
} // namespace media
